'The world's top expert'

It's an optimistic article, sort of.

DNA analysis, the authors say, has provided a scientific standard for forensics. It was developed through a scientific process. It was critiqued by a wide variety of scientists. Standards were developed for conducting DNA tests and for reporting them.

"In DNA, we say, Here are the chances of a match, and here is the frequency with which we make an error," Koehler told me Friday.

By contrast, he said, a ballistics expert might say, in effect, "It's a match. This bullet came through this gun. I know because I'm the world's top expert."

Yet, say the authors, the studies haven't been done that show statistically how singular are the identifying marks of fingerprints, bullets, hair or other evidence.

What's more, "there has been remarkably little research on the accuracy of traditional forensic sciences."

These "sciences" became science largely by saying they were.

Forensic scientists often argue that the science is infallible. Any problems are due to "human error." But as Koehler points out, where the error occurs matters little to the jury, or to the person wrongly imprisoned.

Koehler and Saks propose subjecting crime labs to "blind testing," in which technicians are tested with samples that appear to be part of their regular work. The tests should be conducted by an independent agency, and the results should be made public, as with mainstream science.

"The FBI does their own testing and says, 'We've done our testing and we're perfect, and you can't look at our data because we're the FBI,' " said Koehler.

One of the reasons forensic science is so fallible, the authors write, is that 96 percent of the positions are held by persons with bachelor's degrees or less. By contrast, in "normal science, academically gifted students receive four or more years of doctoral training where much of the socialization into the culture takes place. This culture emphasizes methodological rigor, openness, and cautious interpretation of data."

Forensic science, by contrast, is "an adversarial, crime-fighting culture" where there often is pressure to produce findings that support police and prosecutors.

Koehler thinks we're headed in the right direction, but we have a long way to go.

"Some people twist our words into saying we believe no forensic science should come into court," he said. "I don't believe that. I just believe that we're far better off with forensic science that is real science."

A science that doesn't rank right behind eyewitness errors in sending innocent people to prison.